After a year or more of dormancy, the Phoenix project has started to stir again.

With mock-ups for the springs and limbs, I am figuring the clearances needed inside the field frames for everything to operate smoothly.

The above photo gives some idea of how the wedge system will work. The wedges shown here are just softwood. Ipe seems like a good choice for the final version. The wedges will need to resist some pretty massive crushing forces from the spring.

The spring being made in the above photo will probably not be used to power the final machine. It is just another mock-up to help verify the limb design. When the cord wrappings fill up the circle in the template, the spring will be ready to install in the field frame for a first real look at the clearances involved. We want the spring to be as large as possible and still work within the field frame. Also it is important to make the limb as thick as possible where it goes through the spring. This will not only make the limb stronger at it’s weakest point, but will also force the two haves of the spring apart and so increase the leverage acting on the limb and make it’s action more powerful.